Method UpdateModelNormals

GTE/Graphics/Visual.cpp:44–137

}

bool Visual::UpdateModelNormals()
{
    LogAssert(mVBuffer != nullptr && mIBuffer != nullptr, "Buffer not attached.");

    // Get vertex positions.
    std::set<uint32_t> required;
    required.insert(DF_R32G32B32_FLOAT);
    required.insert(DF_R32G32B32A32_FLOAT);
    char const* positions = mVBuffer->GetChannel(VASemantic::POSITION, 0, required);
    if (!positions)
    {
        return false;
    }

    // Get vertex normals.
    char* normals = mVBuffer->GetChannel(VASemantic::NORMAL, 0, required);
    if (!normals)
    {
        return false;
    }

    // Get triangle primitives.
    uint32_t primitiveType = mIBuffer->GetPrimitiveType();
    if ((primitiveType & IP_HAS_TRIANGLES) == 0)
    {
        // Normal vectors are not defined for point or segment primitives.
        return false;
    }

    uint32_t const numVertices = mVBuffer->GetNumElements();
    uint32_t const stride = (int32_t)mVBuffer->GetElementSize();
    uint32_t i;
    for (i = 0; i < numVertices; ++i)
    {
        Vector3<float>& normal = *(Vector3<float>*)(normals + static_cast<size_t>(i) * stride);
        normal = { 0.0f, 0.0f, 0.0f };
    }

    uint32_t const numTriangles = mIBuffer->GetNumPrimitives();
    bool isIndexed = mIBuffer->IsIndexed();
    for (i = 0; i < numTriangles; ++i)
    {
        // Get the vertex indices for the triangle.
        uint32_t v0, v1, v2;
        if (isIndexed)
        {
            mIBuffer->GetTriangle(i, v0, v1, v2);
        }
        else if (primitiveType == IP_TRIMESH)
        {
            v0 = 3 * i;
            v1 = v0 + 1;
            v2 = v0 + 2;
        }
        else  // primitiveType == IP_TRISTRIP
        {
            int32_t offset = (i & 1);
            v0 = i + offset;